Production of an artificial turf fiber with a non-circular cladding

Abstract

A method for producing an artificial turf fiber, comprising: preparing a core polymer mixture from a core polymer and a thread polymer forming beads within the core polymer; coextruding the core polymer mixture with a cladding polymer component into a monofilament, the core polymer mixture forming a cylindrical core, The cladding polymer component forming a cladding encompassing the core with a non-circular profile; quenching the monofilament; reheating the quenched monofilament; stretching the reheated monofilament to deform the beads into threadlike regions; and providing one or more of the stretched monofilaments as the artificial turf fiber.

1 . An artificial turf fiber, comprising:
 a core; and   two protrusions, each protrusion extending from the core, each protrusion including a cross-sectional profile, the cross-sectional profile of each protrusion including an undulated side.   
     
     
         2 . The artificial turf fiber according to  claim 1 , wherein the cross-sectional profile of each protrusion further includes a smooth side. 
     
     
         3 . The artificial turf fiber according to  claim 2 , wherein the smooth side is either a straight smooth side or a concave smooth side. 
     
     
         4 . The artificial turf fiber according to  claim 3 , wherein each protrusion has a rounded tip, and wherein a curvature of the concave smooth side of each protrusion is configured such that a thickness of each protrusion is decreasing in a direction towards its respective tip. 
     
     
         5 . The artificial turf fiber according to  claim 1 , wherein the undulated side comprises uninterrupted undulations. 
     
     
         6 . The artificial turf fiber according to  claim 1 , wherein the undulated side consists of uninterrupted undulations. 
     
     
         7 . The artificial turf fiber according to  claim 1 , wherein the undulated side includes an undulated section, the undulated section spanning at least 60% of the undulated side. 
     
     
         8 . The artificial turf fiber according to  claim 7  wherein the undulated section comprises uninterrupted undulations. 
     
     
         9 . The artificial turf fiber according to  claim 7  wherein the undulated section consists of uninterrupted undulations. 
     
     
         10 . The artificial turf fiber according to  claim 1 , wherein the undulated side includes 4 notches along a straight baseline of the undulated side. 
     
     
         11 . The artificial turf fiber according to  claim 1 , wherein each protrusion encloses an angle of between 100 and 180 degrees towards the undulated side of the profile. 
     
     
         12 . The artificial turf fiber according to  claim 11 , wherein each protrusion encloses an angle of about 135 degrees towards the undulated side of the profile. 
     
     
         13 . The artificial turf fiber according to  claim 1 , wherein the core has a thickness, and wherein each protrusion has an extension of about 3 times the thickness of the core. 
     
     
         14 . The artificial turf fiber according to  claim 1 , wherein the core has a circular cross-sectional profile. 
     
     
         15 . The artificial turf fiber according to  claim 1 , further comprising a cladding encompassing the core, wherein the cladding comprises the two protrusions. 
     
     
         16 . The artificial turf fiber according to  claim 15 , wherein cladding further comprises two circular sections on two opposite sides of the core, and wherein the two protrusions extend from two other opposing sides of the core. 
     
     
         17 . The artificial turf fiber according to  claim 15 , wherein the core has a diameter of 50 to 600 micrometers, the cladding has a minimum thickness of 25 to 300 micrometers in all directions extending radially from the core, and each protrusion has a radial extension, measured from a perimeter of the core, of the cladding thickness plus 2 to 10 times a radius of the core. 
     
     
         18 . The artificial turf fiber according to  claim 15 , wherein the core comprises a core polymer and a thread polymer, the thread polymer including any one of polyamide, polyethylene terephthalate, polybutylene terephthalate, polyester, and polybutyrate adipate terephthalate. 
     
     
         19 . The artificial turf fiber according to  claim 18 , wherein the cladding comprises a cladding polymer, and wherein the core polymer and the cladding polymer include any one of polyethylene, polypropylene, and a mixture thereof. 
     
     
         20 . An artificial turf, comprising:
 an artificial turf backing; and   the artificial turf fiber according to  claim 1 .